check engine light

[dogpython]

2000 ford focus w/ zetec engine 50,000 miles
replaced spark plugs and the engine began to idle rough and the check engine light came on, ie shaking the car, rechecked plugs, added fuel cleaner and regapped plugs and even replaced old plugs into car and still idled rough
think it might not be a problem with the spark plugs, and just happened to coincide with the spark plug replacement, could it be the egr valve? any suggestion? thanks

edit: plugs are champion double platinum

[Mustangman25]

What kind of plugs?

[mlw35405]

Try checking the trouble codes using the trip odometer

With key off, hold in trip reset and start car, release trip reset when TEST appears. Push the button to scroll through test modes, one push is GAGE test, two pushes is BULB test, and three pushes displays the DTC codes. Write them down and post them and we'll look them up. Turn the car off to return to normal mode.

[dogpython]

Originally Posted by mlw35405

Try checking the trouble codes using the trip odometer

With key off, hold in trip reset and start car, release trip reset when TEST appears. Push the button to scroll through test modes, one push is GAGE test, two pushes is BULB test, and three pushes displays the DTC codes. Write them down and post them and we'll look them up. Turn the car off to return to normal mode.

great advice mlw35405, think we have actually cleared the problem it was a cylinder 4 misfire, we changed plugs and ignition coil and the car seems to be good, however if anyone has any insight into how to clear the cel without a obdII scanner that would be great, or is this the only way to clear it? thanks!

[USD-Trinity]

Hey, I've had the same problem with my focus I'm at 94,000 miles though. I took it in to the Ford Garage and they checked it all out. They said that the Focus has been known to have problems with the valves sticking. So it's either pay $200 to get some kind of combo clean run through it, which might fix it, or get the whole head replaced for around $2000. Hopefully you've already got it fixed though, I know I'm a couple months late in replying but I just got here. In my focus I'm just running those gas additives through it for injector and carb cleaning, it's been getting a little better. I hope it helps!